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HDMI 2.1 Explained: Do You Actually Need It?
Bandwidth is the whole story
| Port | Bandwidth | What it can carry |
|---|---|---|
| HDMI 2.0 | 18 Gbps | 4K at 60Hz · 1440p at up to 144Hz |
| HDMI 2.1 (TMDS) | 18 Gbps signalling | Same ceiling as 2.0, plus 2.1 features such as VRR — check the manual |
| HDMI 2.1 (FRL) | Up to 48 Gbps | 4K at 120Hz · 1440p at 240Hz · 8K at 60Hz |
| DisplayPort 1.4 | 32.4 Gbps (with DSC, more) | Full refresh on almost every monitor we recommend |
HDMI 2.1 replaced the old TMDS signalling with FRL, nearly tripling bandwidth. But the standard allows ports that keep TMDS signalling and add only the feature set — legal "HDMI 2.1" ports with HDMI 2.0 speeds. Manufacturers rarely print which kind a monitor has on the box; the manual's resolution/refresh table is where the truth lives, and it is one of the things our two-source check reads for every pick.
What the features mean
VRR (Variable Refresh Rate) — the display matches the console or PC's frame rate, removing tearing and judder. The feature most worth having for console gaming. ALLM — the display switches itself into its low-latency game mode when a console is detected. eARC — higher-quality audio passed through to a soundbar or receiver; a TV feature that rarely matters on monitors.
Consoles: what PS5 and Xbox actually need
PS5: 4K at 120Hz requires a full HDMI 2.1 port and an Ultra High Speed cable (the one in the PS5 box qualifies). At 1440p, the PS5's 120Hz mode fits within lesser ports on many monitors — our PS5 guide's value pick, the Dell G2724D, runs it with VRR over its TMDS port, which is precisely why that port's limits are printed there.
Xbox Series X|S: 4K at 120Hz likewise needs full HDMI 2.1, but the Xbox also supports 1440p at 120Hz natively, which does not — one reason our Xbox guide can recommend cheaper monitors than the PS5 guide at the same smoothness.
PC: use DisplayPort. Two checked examples from our ultrawide guide: the ASUS VG34VQL3A caps at 100Hz over HDMI but runs its full 180Hz over DisplayPort, and LG's own manual caps the 34GP83A-B at 85Hz over HDMI at full resolution. On PC, HDMI is the second-best cable in the box.
The ports on our picks, checked
| Monitor | HDMI | Full refresh over HDMI? |
|---|---|---|
| MSI MPG 322URX | HDMI 2.1 (full) | Yes — 4K 240Hz class |
| Alienware AW3425DW | 2x HDMI 2.1 (FRL) | Yes — 240Hz over HDMI as well as DisplayPort |
| Samsung Odyssey OLED G9 G93SC | 1x HDMI 2.1 + 1x Micro HDMI 2.1 | Yes (note the micro connector on input 2) |
| LG OLED evo C5 42 | 4x HDMI 2.1 | Yes — 4K 120Hz on every input |
| Dell G2724D | 1x HDMI 2.1 (TMDS) | Up to 1440p 144Hz with VRR — enough for consoles, not 4K 120Hz |
| ASUS VG34VQL3A | 2x HDMI 2.0 | No — 100Hz cap; use DisplayPort for 180Hz |
| LG 34GP83A-B | HDMI 2.0 class | No — 85Hz cap at full resolution per LG's manual |
| MSI G274QPF E2 | 2x HDMI 2.0b | 144Hz cap; 180Hz over DisplayPort |
Cables, briefly
For 48Gbps you need an Ultra High Speed certified cable — the certification, not the price, is what matters, and the cables bundled with the PS5 and Xbox Series X are already certified. Longer runs fail first: past about 3 metres at 4K 120Hz, expect to pay for a certified or fibre cable. A 2.1 cable works fine in a 2.0 port (bandwidth is set by the weaker end), so buying the better cable is never wasted.
Update history
November 10, 2026: Published: HDMI 2.1 bandwidth, the TMDS port trap, and console requirements — with the checked HDMI specs of our picks.
Akbar Khan Editor, BuyBestMonitor
Akbar has run BuyBestMonitor since its original 2020 launch. Every guide here is checked under the site's two-source rule — manufacturer specs confirmed against an independent lab review — before publication and at every refresh. About the editor · How we check monitors